ADC cross-interference

Using Arduino General Electronics
#1

I'm using arduino mini pro. 4 ADC ( A0, A1, A2 A3, ) to convert LDR( light dependent resistor) voltage to digit.
The circuit is like this 5v---5.6K--@--LDR----GND. the measure( ADC) is at @ point. seems four converted value are interference each other. the program read A0, A1, A2, A3 one by one. if they have interference, how to solve it?

thanks
xianwu

#2

Read each Ax twice, use the 2nd reading. Gives the data time to settle.

#3

thanks for your suggestion.
actually, I read each ADC 6 times, remove Max and Min then use the rest 4 for average. and between each read I have 10ms delay.

#4

All that and it's still corrupted? Wow.

#5

LDRs in the dark can have a very high impedance - the ADC needs a drive impedance
of 10k or less to perform to specification - perhaps the sensors need buffering before
the ADC?

#6